One of the problems that may arise during the treatment of HIV and cancer as well as during organ transplants is the risk of infection caused by microorganisms. The development of antibiotics that fight bacterial infections is already well established. The appearance of drug-resistant bacteria such as MRSA and VRE is already causing problems, however, more serious than these are infections caused by fungi. In particular, candidiasis caused by Candida albicans and aspergillosis caused by genus Aspergillus are large obstacles during transplant operations.
Yeasts and filamentous fungi are eukaryotes, and are referred to as fungi in comparison to bacteria, which are prokaryotes. Certain types of fungi exhibit pathogenicity towards humans and animals, and are regarded as causative microorganisms of fungal infections. The pathogenicity of these fungi is generally weak, however, they sometimes cause severe symptoms in patients who already have lowered resistance.
Because the various illnesses generated by fungi have an enormous effect on the health of humans and animals, the development of new medicines that are useful in the treatment thereof is greatly desired. Moreover, the intrusion of filamentous fungi in houses as a result of condensation and the like, which is reflective of modern housing conditions, causes symptoms such as allergies and the like in humans, and has a deleterious effect on the health of humans and animals. The development of new antifungal agents is desired as an effective countermeasure against such phenomena.
Here, preparations that inhibit Candida mycelial growth are described in Patent document 1 and Non-patent document 1.
In Patent document 1 it is disclosed that a synergistic effect in anticandidal activity against in vitro Candida mycelial growth is evident if capric acid (decanoic acid) is used in combination with any one of geraniol, eugenol, or citral. Moreover, it is also disclosed in Patent document 1 that, in oral candidiasis models in mice, a combination of capric acid and ginger essential oil had the greatest effect towards improving tongue symptoms.
Furthermore, it is disclosed in Non-patent document 1 that a synergistic effect in anticandidal activity against in vitro Candida mycelial growth is evident if capric acid is used in combination with terpinen-4-ol. Moreover, it is also disclosed in Non-patent document 1 that, in oral candidiasis models in mice, reliable therapeutic effects including a reduction in the viable bacteria count were apparent when capric acid and terpinen-4-ol were used in combination.
However, the aforementioned Patent document 1 and Non-patent document 1 disclose nothing more than the combined effect of using a medium chain fatty acid such as decanoic acid, which is known to have anticandidal activity, with a terpene alcohol such as terpinen-4-ol, which, in the same way, is also known to have anticandidal activity.
Furthermore, as is shown in Patent document 2, taking note of the fact that a complex of lysozyme and chitosan (30 kDa) has antibacterial properties, applications of this complex to foodstuffs and cosmetics may be considered. This complex is extremely safe, and imparts a stability to the lysozyme whose importance is emphasized by product design and the like, so as to further broaden the antibacterial spectrum.
However, nothing apart from the fact that this complex has antibacterial activity against Escherichia Coli K12 is disclosed, and any antibacterial activity against fungi such as genus Candida and genus Aspergillus has not been confirmed.